1. Field of the Invention
This invention is in the field of weight-shift monitors and analyzers for golf swing practice.
2. Description of Prior Art
Numerous golf stance and movement aids are shown in prior patents, including weight shift monitoring devices of various types. However, none provide the same training feedback as the present invention, and none have achieved its simplicity and effectiveness. Relevant U.S. patents in this field include U.S. Pat. No. 2,189,613 (Paulsen), U.S. Pat. No. 3,352,559 (larsen), U.S. Pat. No. 3,415,523 (Boldt), U.S. Pat. No. 3,639,923 (Stewart), U.S. Pat. No. 4,023,810 (Lorang), U.S. Pat. No. 5,263,863 (Stefani), and U.S. Pat. No. 4,917,385 (Brown).
U.S. Patent 3,352,559 (Larsen) shows a Golf Swing Training Device having a platform mounted on a universally rotatable ball, which allows the platform to tilt in any direction. A stop (18) on the follow-through side limits the platform to a horizontal position in that direction. A shorter stop (20) on the back-swing side allows the platform to tilt in that direction when the Wolfer's weight shifts laterally past the center, which is the error condition. The golfer is thus trained to center his or her weight toward the follow-through side, rather than over the center as with the present invention. Larsen's platform also tilts forward and back, and has respective stops to indicate an error in the forward direction. Electrical contacts are provided to activate an electrical sound generator on each error condition.
U.S. Patent 5,263,863 (Stefani) shows a Weight Shift Trainer for Golfers having two individual foot platforms mounted oh a base. The foot platform on the follow-through side pivots between a horizontal position and an inward-facing position to allow the user to sense a shift of weight via the angle of the leading foot.
U.S. Patent 3,415,523 (Boldt) shows a golfer's Training Device for guiding every aspect of a golfer's swing and stance, and monitoring the golfer's center of weight. The weight monitoring portion comprises a platform (30) mounted on a central pivot point, and stabilized horizontally by springs (34) at the left and right sides between the platform and base (26). A pair of electrical contacts (36 and 38) are provided between the platform and base on thy follow-through side. These contacts are used in conjunction with other switches to train the golfer to shift his or her weight to the back-swing foot on the back-swing, and to the follow-through foot on the follow-through. In contrast, the present invention warns the golfer against shifting the weight toward the back-swing. Boldt's alert timing depends on the golfer's weight. The platform pivots about a single point and is balanced by springs, so a heavier golfer will close the contacts at a smaller distance off-center than will a light golfer. In contrast, the alert timing in the present invention depends only on the distance that the golfer's weight is off center, regardless of the weight of the golfer.